Gas turbines have a compressor where air is compressed, a combustion chamber where a fuel is injected and is combusted with the compressed air generating hot gas, and a turbine where the hot gas is expanded. Downstream of the turbine a diffuser is typically provided to expand and guide the exhaust gas to a stack or to further treatments or to additional components of the plant.
EP 2 679 780 discloses a diffuser; the diffuser has a support structure, insulation and a liner. The liner is made by a plurality of segments that are connected to the support structure and have overlapping borders. Each segment is fixed to one holder in turn connected to the support structure; additional holders are slidingly connected to the segments and are fixed to the holders; this way the segments are supported by the support structure via the holders, but thermal expansion is not prevented.
The overlapping borders are not fixed together, for this reason hot gas pulsations or other gas turbine excitation (e.g. vibration of the structure of the gas turbine) can cause vibration of the liner segments and, in particular, vibration of the overlapping borders. Vibration can cause hammering wear of the overlapping borders with opening of gaps between segments and loss of liner segment pieces.